While digital wristwatches having timekeeping displays have taken on various forms, such wristwatches have been found to have various defects during normal operation. Particularly, digital wristwatches display present or elapsed time, for example 2:23, i.e. twenty three minutes after two o'clock, but they do not present the time remaining within the hour, i.e. 37 minutes.
Prior art patents of interest include U.S. Pat. Nos. 3,950,935 issued Apr. 20, 1976 to Okito Naito; 3,822,547 issued July 9, 1974 to Kinji Fujita; 3,950,936 issued Apr. 20, 1976 to Henri J. Oguey et al; and 3,971,205 issued July 27, 1976 to Yasushi Nomura et al.